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Petrochemical

NSK Bearings for the Petrochemical Industry

Minimising production stoppages and maximising productivity are crucial in the petrochemical industry. The machine components used in this sector – such as pumps, compressors, electric motors, blowers and ventilators – are particularly susceptible to change. These components contain bearings which have to work reliably and precisely, even in challenging conditions.

As one of the world’s leading manufacturers of bearings, NSK is a valuable partner for the petrochemical industry. Our Application Engineers are the first people you should talk to – they have the expertise to work with you on developing solutions that effectively cut costs and boost productivity.

Our specialists are in touch with the research and development teams at OEMs that produce components for petrochemical systems. This enables them to develop new bearing solutions at every level of your project.

Centrifugal Pumps

Centrifugal Pumps

Operating conditions: medium speeds, axial and radial loads

If a process pump fails in a petrochemical plant, this can lead to costly downtime. Centrifugal pumps are used to transport liquids at every stage of the process and are among the most sensitive components used in the petrochemical industry.

Pump applications place a great deal of strain on bearings, meaning that the materials used for bearings and bearing cages have to withstand tough conditions. The bearings have to support axial, radial or combined loads, run equally reliably at low and high speeds (1,500 rpm to 3,000 rpm) and handle different lubrication conditions with ease.

The single-row angular contact ball bearings from the NSKHPS series run extremely reliably in compliance with API standards, especially in difficult applications as centrifugal pumps. They boast a long life, even when exposed to high axial loads.

The special high-strength cage construction makes the bearings in the pumps more resistant to shock loads and vibrations. Thanks to the precisely manufactured guiding surfaces, the noise level is lower than that of conventional bearings.

Special Pumps

Submersible pumps are widely used for water and wastewater applications. They have a vertical driving motor which is connected to the impeller at its extremity. The double-row angular contact ball bearing at the bottom must withstand axial and radial loads, while the deep groove ball bearing at the top is only subject to light radial loads. It is important to avoid creep (relative motion) between the outside diameter and housing of the top bearing.

LNG Pumps

Liquefied natural gas (LNG) pumps are used to load/unload cryogenic liquids in tanks. The bearings used here must be able to withstand a liquid gas temperature of −162°C and are partly lubricated by the pumping medium.

LNG pump bearings from NSK are made from stainless steel, which provides excellent corrosion resistance. They also feature a specific cage made from fluororesin. This material is extremely useful as it is self-lubricating even at very low temperatures.

Compressors

Roots Blowers

Roots blowers are rotary piston blowers which are often used to transport gas. The gas is carried from the intake side to the exhaust between the lobes of the rotors and the outer wall and compressed by the backflow. This can generate some vibrations, which bearings must be capable of withstanding.

Oil-Injected and Oil-Free Compressors

Operating conditions: oil lubrication, medium to high speeds, medium to high axial and radial loads

Two screws are used to compress gases. The gas enters on the inlet side and flows through the threads while the screws rotate. As the compression space becomes smaller, the gas is compressed. This process requires bearings that can withstand high radial and axial loads and enable precise shaft positioning.

NSK has developed special angular contact ball bearings and cylindrical roller bearings for oil-injected screw compressors. The bearings come with an L-PPS cage. NSK’s patented material L-PPS (linear polyphenylene sulphide) is ideal for use in screw compressors thanks to its outstanding resistance to heat and wear and its high strength and chemical stability.

Thanks to the materials used and special internal design, NSKHPS spherical roller bearings work precisely and reliably, even at limiting speeds up to 20% higher than conventional designs. We have also succeeded in increasing the dynamic load rating by up to 25%. The bearings are wear- and temperature-resistant. Their long service life also makes for lower maintenance costs.

Electric Motors

Operating conditions: high temperature, high speeds, vibrations

Electric drives for pumps, compressors, blowers and conveyor belt systems have to withstand high operating temperatures and high speeds.